Donald Trump headed down the aisle for the third time yesterday – to share vows with stunning Slovenian supermodel Melania Knauss in a lavish Palm Beach wedding.

Hundreds of celebrities and power brokers including Bill Clinton and Rudy Giuliani flocked to Florida for the all-out festivities, which began with a ceremony in an oceanside church, followed by an opulent reception at Trump’s country club, Mar-a-Lago.

The marriage of the 58-year-old billionaire star of “The Apprentice” to the bodacious, 34-year-old Knauss has already been dubbed the social circus of the season and some 1,500 fans lined the streets to catch a glimpse of the happy couple and their glitzy guests.

For his latest merger, the two-time divorcee wore a black tux, with white tie and cummerbund, from Brioni, but the bride stole the show.

Some 400 guests in the church, many who had arrived an hour early to snag good seats, leaped to their feet to ogle Knauss’s $200,000 handmade Christian Dior gown, as she walked up the aisle to a solo of Ave Maria.

While Knauss didn’t carry a bouquet or have bridesmaids, she and Trump stuck to tradition when exchanging vows at the Episcopal Church of Bethesda-by-the-Sea. They promised to love, honor and obey each other, with some guests unable to suppress sniggers when the pair said “for richer for poorer.”

After exchanging vows, the couple kissed three times to cheers and left the church in a shower of white rose petals. They then slipped into Trump’s Mercedes-Benz Maybach and sped off with a police escort.

Guests followed, causing a three-mile traffic jam of limos as they headed for Trump’s 18-acre mansion-turned-country club overlooking the Atlantic, where the reception was being held in a $35 million, Versailles-inspired ballroom.

Staff had spent days putting the finishing touches on the lavish gold-leaf, mirrored room, including laser lights and a spotlight shining the Trump crest.

Yesterday morning, before his nuptials, Trump was up early to play golf at his course near the Palm Beach airport and was talking as if it was any other day, according to sources at the TV show “The Insider.”

The Donald even remarked to his golf buddies, Donald Jr. and NBC’s Billy Bush, “I keep forgetting that I’m getting married later today.”

Spies said The Donald made the rounds at the bash where guests feasted on a buffet of various salads, pasta, roast beef, chicken, lamb, prime rib, lobster, oysters and caviar – and a array of desserts including key lime pie, chocolate mousse cake, cheesecake and finger-size desserts.

The actual cost to Trump for his third wedding is a bit of a mystery. Some are suggesting that, thanks to a slew of endorsements and deals, a profit is possible.

Trump reportedly paid half-price for Knauss’ $1.5 million engagement ring and set up an exclusive deal with Getty Images to sell photos of the wedding for an undisclosed amount.

That deal alone stands to make Getty $1 million, including a $375,000 deal with People and InStyle magazines, industry sources told The Post.

Cameras, recording devices and cellphones were banned from the wedding to preserve Trump’s exclusive photo contracts – a message that was put in wedding invitations engraved by Tiffany and Co.

Trump was once even excited by an NBC offer to telecast his wedding live – until Knauss put her well-heeled foot down and vetoed it.

Jean-Georges Vongerichten, whose four-star restaurant is a tenant at Trump International Hotel & Towers in New York, was reported to be providing a $43,000 dinner for free to the hundreds of guests. It included fillet mignon with green peppercorn sauce and steamed shrimp.

As for the honeymoon, despite the lavish festivities there won’t be one for The Donald and Mrs. Trump No. 3.

“I’m not a big vacation person,” Trump said during a recent news conference. Instead, say spies, the newlywed plans to play some golf.